Cold perforation of extensible films
Efficient and precise perforation with less dust: A new process for elastic films
Perforation plays a crucial role in the processing of elastic plastic films—especially when it comes to targeted air permeability. A common problem here is the tearing of the holes, which is accompanied by dust formation. A well-known manufacturer of elastic films approached the German company tambula with this challenge. The question was: How can an elastic film be perforated with precisely uniform hole diameters – without excessive material abrasion?
The cause: “Caps” instead of clean holes
The root cause analysis revealed that the elastic film often gets caught on the needles during the perforation process. Instead of piercing through immediately, the material wraps itself around the needle until small, dome-like “caps” form, which then tear out. This tearing of the material produces fine perforation dust, which can interfere with downstream processes. In addition, the snagging leads to significantly more uneven hole diameters, which impairs the quality of the end products.
The solution: a patented two-stage process
tambula then developed an innovative two-stage process, which has since been successfully patented. The technology: The film is not perforated in a single step, but undergoes two coordinated perforation steps. In the first step, only a slight perforation is made. This pre-weakening significantly reduces the resistance of the film in the second step. The subsequent, deeper perforation can thus be carried out with significantly less force – friction is reduced and the formation of beads is largely prevented. Material abrasion is visibly reduced, which can potentially save on suction.
Machine technology: powerful, precise, and flexible
A first machine with this innovative perforation solution is already being used successfully in production by a plastic film manufacturer. To enable the high perforation forces while ensuring gentle processing of the material, the machine is equipped with a powerful servo motor. This not only enables precise force control but also ensures consistently high process stability over long running times. The machine is designed as a compact, integrated unit and is easy to move. As with all tambula perforation systems, all the electronics are mounted directly on the frame – a true “plug-and-play” system that is ready for immediate use without any complicated installation. Of course, modern safety technology and an ergonomic user interface are also included.